A printer head for a Braille printer is previously known from U.S. Pat. No. 4,735,516. This printer head includes a rigid frame that is made up of a number of elements that can be displaced along guide rails. The frame supports a number of solenoids that have a needle/small rod at one of their ends that interacts with a counter hole, also supported on the frame, in the form of an indentation/die cushion to form the raised dots on Braille paper positioned between the needle and the counter hole when the solenoid is activated and displaces the needle towards the counter hole.
To make the manufacture of a frame for a printer head for a Braille printer more efficient, a technique has been developed where the said frame has the form of a housing that usually consists of two extrusion moulded parts, preferably extrusion moulded aluminium, that are joined together to form the said housing. One of the frame parts supports the solenoids with the needles while the other frame part supports the counter holes/die cushions. To allow the Braille paper onto which the raised dots are to be introduced to pass through the printer head and past a space formed in the housing in which the needle and the counter hole have their effect, the said parts are usually designed so that between themselves they have opposing slit-shaped openings. However, a major problem with this construction design is the mutual positioning accuracy of the mounting positions that accommodate the solenoids respective die cushions, whereby the mounting of the solenoids and dies respectively, for example by means of screwing, takes place from the sides of the frame parts that, when they are to be joined together, are turned to face one another. When the frame parts have been joined together, it has been shown that it is extremely difficult to obtain sufficiently exact tolerances regarding the above named mutual positioning accuracy between the solenoids and the associated die cushions. Here it should be pointed out that the correct accuracy of this positioning is of crucial importance for the whole construction. If this is not accurate, the Braille paper can be damaged and the result will not be fully acceptable as a raised dot. To try and correct this problem, adjustments have had to be made afterwards, which is time-consuming and costly. In addition, the final result has often not been satisfactory, despite this subsequent adjustment.